Motor-controller.



G. T HENDERSON. MOTOR CONTROLLER.

APPLICATION TILED APR.23,1909.

Patented Sept. 1, 191&

IN vzzvrma' Qlark Tflkndenson.

WITNESSES .ATTYI UNITED STATES PATENT OFFICE.

CLARK T. HENDERSON, OF MILWAUKEE, WISCONSIN, A'SSIGNOB. TO THE CUTLER- HAMMER MFG. CO., 01 MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

moron-conmmzn.

Application filed April 38, was. Serial 10,401,810.

To'all whom it'may concern Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in MotonControllers, of which the following is a full, clear, concise, and exact description, reflerence being had to the accompanying drawing, forming a part of this specification.

iIy invention relates to controllers for electric motors, and more particularly to controllers adapted to automatically accclerate the motor. In controllers of this type,

it is advantageous to provide one or more throttling devices to rheck the removal of the starting resistance from the motor circuit upon the occurrence of abnormal conditions. While such. throttling devices check the removal of the starting resistance from circuit upon an excessive How of current, yet they in no wise retard the acceleration of the motor unless ahnormai conditions do occur during the-starting period. Hence, if the load is very light, the throttling devices are not likely to respond, and consequently the motor is brought up to normal speed in a very short time. To bring the motor up to speed in the shortest possible time is very advantagmus in many instances. in some instances, however, as

in elerutor service, too rapid acceleration of the motor. even though without danger of injuring the motor, is objectionable in that it starts the car with more or less of a jerk, therebv causing discomfiturc of the passengers f course, where the load is heavy, there is very little likelihood of the motor accelerating so rapidly as to jerk the car in starting. but where the load is very light, this often occurs.

It is, therefore, the object of my invention to provide means, in addition to the throttling! devices heretofore mentioned. which will insure at least a predetermined lapse of time before the motor is brought up to full speed, regardless of its load.

I further provide means whereby the minimum length of time required to bring the, motor till i0 normal speed may be varied as desired. v

For the purpose of more fully (lls(l 8 lllg the churacu-ristic features of my invention,

l I shall describe theembodiment thereof Be it known that I, CLARK: T. HENDERSON, a citizen ofthe United States, residing at illustrated'in the accompanying drawing.

Qf course, my invention is susceptible of various modifications,-thesystem shown in the drawing merely serving to illustrate one form thereof.

The system of control, which I have shown, includesa; main switch 1; resistance switches- 2, 3 and 4; throttling switches 5, Gand 7, and a" relay'device 8. The main switch 1 is provided with an operating winding 1 and the resistance switches :2, 3 and 4, with operating windings 2", 3 and 4, respectively. The throttling devices 5. ti and 7 areprovidcd with controlling windings 5', 6 and 7, respectively. The resistance twitches 2, 3- and 4 are arranged to control resistances R, --R- and R, arranged in the circuit ofi the motor which, 2.5 shown. is provided w ithan armature A. and a field winding" F. =The plunger of the operating winding of the main switch 1 carries a pair or" contact disks Q and 9, each adapted to engage a. pair ofistat-ionury contacts. The plungers of-the operating windings 2' and 3' of the resistance switches Q and 3 each carrya similar pair of contact disks 10, 10, 11 and 11 respectively. The plunger of the winding? carries a single contact disk 12, adapted to engage a pair of stationary contacts. The relay 8 comprises a solenoid, having a winding 13 and a core 14, which carries contact 'disks 15 and 16. The contact disk 15 is adapted, when in one position, to engage a pair of contacts 17, and when in another position to engage a pair of contacts 18. The contact disk 16 is adapted to engage a pair of contacts 19. The contacts 17 are bridged by a moist- M106 1'', while the contacts 18 are bridged by a resistance 1-. The contacts 19 are bridged by a resistance r. The tail rod of the core 14- of the winding 13 is coir nected to the lunger of a double acting dash-pot Q0. which, of course, retards the movement of the core 14 in both directions. This daslnpot may be of any preferred form, and may advantageously be provided with some means of adjustment for the purpose hereinarlter set forth. Curmnt is suppliedrto the motor and to the various windings from main lines 30 and 31 through a double pole switch 32. Another switch Patented Sept. 1, 1914.

til

27, adapted to engage contacts 28 and 29, is provided for the purpose hereinafter set forth. j

ll. shall now describe the operation ofithe controller.

Upon closure of the switch 32 circuit is closed by conductors 33 and 34:, through auxiliary contact 9- of the main switch 1 by conductor 35 through the operating winding of the relay 8 by conductors 3b 'atingwinding oi the main switch 1 from conductor 33 through said winding by conductor 410 through the auxiliary contact 10" of the resistance switch 2 by conductor ll.

through the auxiliary contact 12 of the switch 4 by conductors 37, 38 and 39, to the negative side of the main line. The winding 1 being energized, closes the main switch 1, which closes the motor circuit from conductor 33 through switch it by conductor l2 through the winding of the throttle switch 5 and through the resistances R, and R by conductor 43 through the motor armature it. and series field winding F by conductor let to the negative line. motor is started with all the resistance in circuit. Upon closure of the main switch 1, the contact disk 9 is moved into engagement with its stationary contacts. This completes a circuit from switch 27 by conductor l5 through contact disk 9' throttle switch 5, conductor 46, through the winding 2- by conductor 47 through resistance 1' by con-.

ductor -18 to the negative line. Owing to the inclusion of the resistance r in the circuit of the winding 2, said winding is not sufliciently energized to close the switch 2. However, when the auxiliary contact 9 of the main switch engages its contacts, the auxiliary switch 9 is disengaged from its contacts, which results in opening the circuit of the winding l3 oi the relay device 8. Hence, the plunger 1% of the relay device is permitted to ,d'eswnd against the action of the dash-pot 2t). Alter a predetermined interval, according to the adjustment of the dash-pot 20, the contact 15 will engage the contacts 18, thereby short circuiting the resistance r? in circuit with the winding 2. 'lhereupon said winding will become tally energized, assuming that the throttle switch 5 is in ncrmal osition. As soon as the winding 2 is t" ly energized, it closes the switch 2, which removes the resistance R from the motor circuit. Should, however, the throttle switch? be opened before the switch 2 is closed, said switch 2 cannot be Thus the 1 closed until'after normal conditions are restored and the throttle switch 5 returns to normal position, owing to the fact that in open position the throttle switch '5 interrupts the circuit of the winding 2. It will be seen, however, that with this arrange.

switch 1 and the resistance switch 2, re-

gardless of whether or not the throttle, device has in the meantime responded. Qt course, the operation of the throttle switch 5 may prolong the interval between the closure of the main switch and the first resistance switch. in such an event, the relay device willhave time to operate before the throttling switch returns to normal position, and, hence, it will not further retard the operation of the accelerating switch. Upon closure of the switch 2, the circuit of the winding 1 of the main switch is interrupted at the contact disk 10, thereby inserting a resistance 4:9 in circuit with the winding 1. This establishes a high resistance maintaining circuit for the main switch, which may be traced from conductor 40 through resistance. 4:9 to conductor 39. Also upon closure of the switch 2, circuit is again closed through the operating winding 13 of the relay device 8, and also through the operating winding 3 of the switch 3. The latter circuit may be traced from conductor 46 through the auxiliary contact 10 of the switch 2 through the throttle switch 6 by conductor through said winding 3 by conductor 51, through the resistance r and conductor 48 to the negative line. Owing to the inclusion of the resistance r in this circuit, said winding will not be sufliciently energized to close the switch 3. However, as before stated, circuit is at this time closed through the winding 13 of the relay device 8, and-may be traced from conductor 46, across contact disk 10 by conductor 52 to conductor 35 through the winding 13 and thence back to the negative line, as already set forth. The plunger of the relay 8 is thereby raised against the action of the dash-pot 20, and after a predetermined interval of time, according to the adjustment of the dash-pot, the contact 15 will bridge the contacts 17, thereby removing the resistance r from'the circuit of the winding 3. The winding 3 will then respond and close the switch 3, assuming that the throttle switch 6 is closed. Closure of the switch 3 removes the resistance R from the motor circuit. Should the throttling device 6 re.- spond to an excessive flow of current before the switch 3 is closed, the interval between the closure of the switches 2 and 3 might be prolonged, .but at any rate, a predetermined lapse of time between the closure of the switches is insured by the relay 8. Upon closure of the switch 3, circuit is closed from through resistance 1?, and by conductor 48- to thenegative side of the main line. The

switch 4 cannot :immediately close, owing to the inclusion of the resistance r in the circuit of its operating winding. However, upon closure of the switch 3, the circuit of the winding 13 of the relay 8 is opened at contact disk 11, which permits the contact 16 of the-relay to descend against the action of-the dash pot 20. The contact 16 then short circuits the resistance 1", thereby permitting-the: switch 4 to close unless prevented by the throttle switch 7 Here, again, it will be seen that at least a predetermined lapse of time is insured between the closure of-the switches 3 and 4. As the switches 2,

3 and 4 close successively, they graduallyremove the residzances R, R and R from circuit, thereby gradually accelerating the motor. Closure of these switches also re-- sults in short circuiting their correspond: ing throttling devices, thereby rendering the same inefiective to cause said switches to open after they. have once been closed. Upon closure of the switch 4, the contactdisk :12 is disengaged from its contacts. Here it should be noted thatwthe energizingcircuit of the, winding-ofthemain switch is com pleted. throllghthscontact disks 10, 11 and 12 of the resistance switches. Hence, when any of these contact disks are actuated by the closure of their respective resistance switches, the resistance 49 is inserted in circuit with the winding of the main switch. The resistance 49 being'proportioned to reduce the flow of current through said winding toan amount just suificient to maintain the main switch closed, but insufiicient to close the same, it will be seenthat when the main switch is once opened, it cannotbe again closed until all of the resistance switches open to r turn the contact disks to initial position.

With the arrangement set forth, it will be seen that I provide for at least a definite lapse of time between the closure of successive accelerating switches, even though ing switches will operate immqliately upon the return of the throttling switches to initial position. Furthermore, it will be seen that by adjusting the dash-pot of the relay device, the minimum lapse of time between the closure of successive switches may be varied as desired, thereby insuring an Lminimum lapse of timebefore the motor is rought to normal speed.

Of course, my invention is not limited to any particular form of relay device, nor is it limited to any particular form of controller.

I Havin thus described my invention, what I c aimas new and desire to secure by Letters Patent, is-

1. In a controller for electric motors, in combination, a plurality of succemively operated switches having individual operating means and a single automatic device for controlli said switches to insure a predetermined apse of time between the operation of successive switches, said device be? ing controlled by said switches to operate irrespective of the motor current.

2. In a controller for electric motors, in combination, a plurality of switches,- a plurality of electromagnetic windingsv foropcrating said switches successively, and a single automatic device controlling said windings to insure a predetermined lapse of time. between the operation of successive switches, said device being controlled b said switches to operate independently o current conditions of the motor circuit.

3. In a controller for electric motors in combination means for accelerating the motor bystcps and means controlled exclusivelyby said first mentioned means and operating independently of current conditions in the-motor circuit for insuring a definite timeinterval between successive steps of acceleration.

4. In combination, means for accelerating the motor by steps, means controlled by said first mentioned means for insuring a definite time interval between successive steps of acceleration and means independent of said second mentioned means for arresting the operation of'said first mentioned means while abnormal conditions prevail in a mo tor circuit.

5. In a motor controller for electric motors, in combination, a plurality of electrd responsive switches and automatic means electrically controlled directly by said switches and operating independently of the current conditions of the motor circuit for preventing the. response of each of said switches until a preceding switch has respondedand said means has been operated, thereby insuring a definite interval between the closure of successive switches.

6. In a controller for electric motors, in combination, .a plurality of switches, a pluralityof successively energized windings for operating said switches, a separate resistance in circuit with each of said windings for rendering the same ineffective to close its corresponding switch, and automatic means controlled by said switches for removing the resistance in circuit with the windcuit with the winding of eachiswitch upon the lapse of acpredeterrnincd time after the operation "of wpreceding switch. v

8. lln a controller: for clectricmotors, in: combination, H a plurality of electromagnetifi resistance switches arranged to' operate successively, a plurality of mechanically connected relay switches each: arranged te control the f operating winding otone of said resistance switches, each of said relay switches-tending "to-move automatically to cause the-energiz'aticn of its core responding windingflupon the operation of one of said resistance switches and means for retarding the operation of each 01E- said relay switches for a predetermined time. r

9. In a vcontroller. tor electric motors, in combination, a plurality jot electromagnetic resistance switches arranged to opera% sue cessively, a plurality of relay switches, each arranged to control the'operating winding of one of said resistance switche isaid relay switches being arrcnged to' ino e together and to move alternately in opposite directions to cause the energization of the operat ing windings of said resistance switches, means for retarding the operation of said relay, switches tor a predetermined time, when the same move in either direction-, and an .electromagnct for moving said relay switches in one direction, said electromagnet being arranged to he alternately energized and deenergized as said resistance switches successively operate.

10. In a controller for electric motors,-in combination, a plurality of successively actuated switches, means .for checking the'successive operation of-suid. switches upon the; occurrence: of abnormal conditions in the motor circuit find en eutorimtic time relay controlled by said switches and independent of said means for insuring a definite time icence interval between the operation'ot successive switches.

11. in a controller for electric motors, in

combination, a plurality of successively cc tuated- 'switches, means for checking the-suc-' ccssive' operation of said switches upon occurrence -l of elonormsl conditions in athe motor circuit and an automatic time relay controlled by said switches for insuring definite time. interval between the operation or successive-switches, said relay hrivinggrno retarding effectf said means prolongsithe intervals between the operation of successive switches. v i I 12; in a: motor controller, in comhmetlon,

a pluralitylof electromagnetic switches are ranged to o crate successively, e controlling" switch for t e operating" winding ct each of said 'resnstance SWItCllQS," each oii sand 1 @UH.

trolling switches being adept-ed to automatically operate upon the closure oi one cit said resistance switches to cause the energization of the winding of its'coirespondihg resist- -ance'switch,,means for retarding the operas tion of each of said controlling'ewitches tor a predetermined time, and an electroresponsive throttling switch in circuitqwith the :operating winding oi; eachfof said resistance switches for further checking the successive operation ot said resistance switches upon the occurrence of ahnormalconditions.

l3i lln a controller for electric motors, in combination, a plurality of electromagnetic resistance switches, each of said switches whenclosed heing adapted to complete the. circuit oi the operatingiwinding ot the next succeeding switch, an automatic controlling switch in circuit with-the operating'winding' of. each resistance switch, saidxcontrolling switches being arranged to insure the lapse of a'vprcdetermined time between the closure of successive resistance switches, :and an electroresponsivethrottling; switch in circuit with the operating winding of each resistr ance switch, said throttling switches-lacing adapted to check the successive operationoi said resistance switches upon the occurrence of ahilormalficonditions.

In witness whereof, I have hereunto subscriloed'my name in the-presence of twowitnesses. I

erlAsirr. HENDERSON. I Witnesses FRANK H. Housman, S1. W..-l rrz GERALD. 

